1. Field of the Invention
This invention relates to an antenna, which is mounted on a notebook personal computer, UMPC (ultra mobile personal computer), netbook, mobile phone, PND (personal navigation device), sensor network terminal, or the like, and which is for transmitting or receiving electromagnetic signals, and a wireless device having the antenna.
2. Description of the Related Art
There has been suggested a planar multi-antenna (e.g. refer to JP Patent No. 3690375), which is employed for wireless communications, by being adaptable for wireless systems, such as WWANs (Wireless Wide Area Networks), WLANs (Wireless Local Area Networks), RFID (Radio Frequency Identification), WiMAX (Worldwide Interoperability for Microwave Access), Bluetooth, LTE (Long Term Evolution) and the like, and by being built into wireless communications terminals (wireless devices), such as notebook personal computers, UMPCs, netbooks, mobile phones, PNDs, sensor network terminals, and the like, which are compatible with those wireless systems.
The planar multi-antenna is small in size so as to be suitable for being built into the wireless communications terminals, and is operable in a plurality of frequency bands used for communications.
FIG. 23 shows one example of the conventional planar multi-antenna.
As shown in FIG. 23, the planar multi-antenna 231 is equipped with an antenna element 232 to transmit or receive electromagnetic signals, a ground conductor 233 to be grounded, and a power feed portion 234 for being connected to a feed system. The antenna element 232 is structured to have a plurality of rectangular conductors (which are rectangular in plan view) combined therein.
Refer to JP Pat. No. 3690375, for example.